LT Aaron S. Cantor, MD

A 45-year-old African American woman presented with painless fingernail detachment and cracks on her fingernails that had developed over the previous month. Her medical history was notable for an episode of Stevens-Johnson syndrome 2 months prior that required treatment with prednisone, IV immunoglobulin, etanercept, acetaminophen, and diphenhydramine.

A physical examination revealed multiple fingernails on both hands that exhibited 4 mm of proximal painless nail detachment with cream-colored discoloration, friability, and horizontal splitting (Figure). New, healthy nail was visible beneath the affected areas. Toenails were not affected.

• What is your diagnosis?
• How would you treat this patient?

Diagnosis

Based on the timing and characteristics of her nail detachment, the patient was diagnosed with onychomadesis, which is defined as painless detachment of the proximal nail plate from the nail matrix and nail bed after at least 40 days from an initial insult. Air beneath the detached nail plate causes a characteristic creamy-white discoloration. The severity of onychomadesis ranges from transverse furrows that affect a single nail without shedding, known as Beau lines, to multiple nails that are completely shed.^1,2 Nail plate shedding is typical because the nail matrix, the site of stem cells and the most proximal portion of the nail apparatus, is damaged and transiently arrested.

Various etiologies can halt nail plate production abruptly within the matrix. These typically manifest ≥ 40 days after the initial insult (the length of time for a fingernail to emerge from the proximal nail fold).² The annual incidence of these etiologies ranges from approximately 1 per 1 million people for Stevens-Johnson syndrome, a rare cause of onychomadesis, to 1 per 10 people for onychomycosis, one of the more common causes of onychomadesis.³ The Table compares the characteristics of the diagnoses that are most commonly associated with nail detachment and discoloration.

When a single nail is affected, the etiology of onychomadesis usually is primary and local, including mechanical nail trauma and fungal nail infections (onychomycosis).^1,2 Candida onychia is onychomycosis caused by Candida species typically Candida albicans, which result in localized nail darkening, chronic inflammation of the paronychial skin, and cuticle loss. The infection favors immunocompromised people; coinfections are common, and onychomadesis or onycholysis can occur. Unlike onychomadesis, onycholysis is defined by painless detachment of the distal nail plate from the nail bed, but nail shedding typically does not occur because the nail matrix is spared. The preferred treatment for Candida onychia is oral itraconazole, and guided screenings for immunodeficiencies and endocrinopathies, especially diabetes mellitus, should be completed.^3,4

Tinea unguium is another form of onychomycosis, but it is caused by dermatophytes, typically Trichophyton rubrum or Trichophyton mentagrophytes, which produce white and yellow nail discoloration followed by distal to proximal nail thickening and softening. Infection usually begins in toenails and demonstrates variable involvement in each nail as well as asymmetric distribution among digits.³ This condition also may eventuate in onychomadesis or onycholysis. Debridement followed by oral terbinafine is the treatment of choice.⁴

Two other causes of localized nail discoloration with or without nail detachment include melanonychia and nail bed infection by Pseudomonas aeruginosa (P aeruginosa). Melanonychia can be linear or diffuse brown discoloration of 1 or more nails caused by melanin deposition. Either pattern is a common finding in dark-skinned people, especially by age 50 years, but melanocyte hyperplasia should be excluded in all individuals along with drug adverse effects, exogenous pigments, infections, and systemic diseases.^3,5 P aeruginosa produces pyocyanin, the green pigment responsible for the discoloration seen in this opportunistic infection often localized to a single nail. Prior maceration of the nail apparatus by repeated water submersion is common among affected individuals. Avoidance of submerging fingernails in liquids followed by nail debridement and oral antipseudomonal antibiotics is the preferred treatment course.³

The etiology is usually secondary and systemic when multiple nails demonstrate onychomadesis, but the exact pathophysiology is poorly understood. One of the most studied infectious etiologies of onychomadesis is hand-foot-and-mouth disease (HFMD), which typically affects children aged < 10 years. Parents often will recall their child being ill 1 to 2 months prior to the nail findings. Scarlet fever and varicella also can result in onychomadesis. Although not common systemic causes, Stevens-Johnson syndrome and toxic epidermal necrolysis can trigger onychomadesis of multiple nails that usually resolves in several months, but other nail deformities often persist.^2,6 Onycholysis also can accompany this finding.⁷ Autoimmune etiologies of onychomadesis include alopecia areata and pemphigus vulgaris. Inciting medications that are toxic to the nail matrix include chemotherapy agents, valproic acid, carbamazepine, lithium, and azithromycin. Rare congenital disorders and birth trauma also can present with onychomadesis of multiple nails during infancy.²

Systemic etiologies typically affect fingernails more than toenails because of the faster growth rate of fingernails. Once the source of onychomadesis is controlled or eradicated, complete regrowth of fingernails can take from 4 to 6 months. Toenails can take twice as long and older age increases all regrowth periods.⁵

Our patient was treated with analgesics until her mucosal surfaces fully healed, and topical emollients and keratolytics were used to soften eschars from previous blisters and prevent further scar formation. Her affected fingernails shed and regrew after 6 months without additional interventions.

Conclusion

Although Stevens-Johnson syndrome is a rare cause of onychomadesis, and the pathophysiology of this sequela is poorly understood, this case illustrates a common nail abnormality with multiple potential etiologies that are discerned by an accurate history and thorough exam. In the absence of decorative nail polish, nails can be easily examined to provide helpful clues for past injuries or underlying diseases. An understanding of nail growth mechanics and associated terminology reveals the diagnostic and therapeutic implications of proximal vs distal nail detachment, the hue of nail discoloration, as well as single vs multiple affected nails.

Onychomadesis in single nails should prompt questions about nail trauma or risk factors for fungal infections. Depending on the etiology, manual activities need to be adjusted, or antifungals need to be initiated while investigating for an immunocompromised state. Onychomadesis in multiple nails in children should raise suspicion for HFMD or even birth trauma and congenital disorders. Multiple affected nails in adults should prompt guided questions for autoimmune diseases and inciting medications. For onycholysis, trauma, psoriasis, or certain infections should be the target. Green nails are easily recognized and treated with a defined regiment, whereas dark nails should be examined closely to differentiate Candida onychia from melanonychia. Whether from a rare cause in an adult to a common illness in a child, primary care providers have sufficient expertise to diagnose and treat various nail disorders and reassure worried patients and parents with an understanding of nail regrowth.

A 45-year-old African American woman presented with painless fingernail detachment and cracks on her fingernails that had developed over the previous month. Her medical history was notable for an episode of Stevens-Johnson syndrome 2 months prior that required treatment with prednisone, IV immunoglobulin, etanercept, acetaminophen, and diphenhydramine.

A physical examination revealed multiple fingernails on both hands that exhibited 4 mm of proximal painless nail detachment with cream-colored discoloration, friability, and horizontal splitting (Figure). New, healthy nail was visible beneath the affected areas. Toenails were not affected.

• What is your diagnosis?
• How would you treat this patient?

Diagnosis

Based on the timing and characteristics of her nail detachment, the patient was diagnosed with onychomadesis, which is defined as painless detachment of the proximal nail plate from the nail matrix and nail bed after at least 40 days from an initial insult. Air beneath the detached nail plate causes a characteristic creamy-white discoloration. The severity of onychomadesis ranges from transverse furrows that affect a single nail without shedding, known as Beau lines, to multiple nails that are completely shed.^1,2 Nail plate shedding is typical because the nail matrix, the site of stem cells and the most proximal portion of the nail apparatus, is damaged and transiently arrested.

Various etiologies can halt nail plate production abruptly within the matrix. These typically manifest ≥ 40 days after the initial insult (the length of time for a fingernail to emerge from the proximal nail fold).² The annual incidence of these etiologies ranges from approximately 1 per 1 million people for Stevens-Johnson syndrome, a rare cause of onychomadesis, to 1 per 10 people for onychomycosis, one of the more common causes of onychomadesis.³ The Table compares the characteristics of the diagnoses that are most commonly associated with nail detachment and discoloration.

When a single nail is affected, the etiology of onychomadesis usually is primary and local, including mechanical nail trauma and fungal nail infections (onychomycosis).^1,2 Candida onychia is onychomycosis caused by Candida species typically Candida albicans, which result in localized nail darkening, chronic inflammation of the paronychial skin, and cuticle loss. The infection favors immunocompromised people; coinfections are common, and onychomadesis or onycholysis can occur. Unlike onychomadesis, onycholysis is defined by painless detachment of the distal nail plate from the nail bed, but nail shedding typically does not occur because the nail matrix is spared. The preferred treatment for Candida onychia is oral itraconazole, and guided screenings for immunodeficiencies and endocrinopathies, especially diabetes mellitus, should be completed.^3,4

Tinea unguium is another form of onychomycosis, but it is caused by dermatophytes, typically Trichophyton rubrum or Trichophyton mentagrophytes, which produce white and yellow nail discoloration followed by distal to proximal nail thickening and softening. Infection usually begins in toenails and demonstrates variable involvement in each nail as well as asymmetric distribution among digits.³ This condition also may eventuate in onychomadesis or onycholysis. Debridement followed by oral terbinafine is the treatment of choice.⁴

Two other causes of localized nail discoloration with or without nail detachment include melanonychia and nail bed infection by Pseudomonas aeruginosa (P aeruginosa). Melanonychia can be linear or diffuse brown discoloration of 1 or more nails caused by melanin deposition. Either pattern is a common finding in dark-skinned people, especially by age 50 years, but melanocyte hyperplasia should be excluded in all individuals along with drug adverse effects, exogenous pigments, infections, and systemic diseases.^3,5 P aeruginosa produces pyocyanin, the green pigment responsible for the discoloration seen in this opportunistic infection often localized to a single nail. Prior maceration of the nail apparatus by repeated water submersion is common among affected individuals. Avoidance of submerging fingernails in liquids followed by nail debridement and oral antipseudomonal antibiotics is the preferred treatment course.³

The etiology is usually secondary and systemic when multiple nails demonstrate onychomadesis, but the exact pathophysiology is poorly understood. One of the most studied infectious etiologies of onychomadesis is hand-foot-and-mouth disease (HFMD), which typically affects children aged < 10 years. Parents often will recall their child being ill 1 to 2 months prior to the nail findings. Scarlet fever and varicella also can result in onychomadesis. Although not common systemic causes, Stevens-Johnson syndrome and toxic epidermal necrolysis can trigger onychomadesis of multiple nails that usually resolves in several months, but other nail deformities often persist.^2,6 Onycholysis also can accompany this finding.⁷ Autoimmune etiologies of onychomadesis include alopecia areata and pemphigus vulgaris. Inciting medications that are toxic to the nail matrix include chemotherapy agents, valproic acid, carbamazepine, lithium, and azithromycin. Rare congenital disorders and birth trauma also can present with onychomadesis of multiple nails during infancy.²

Systemic etiologies typically affect fingernails more than toenails because of the faster growth rate of fingernails. Once the source of onychomadesis is controlled or eradicated, complete regrowth of fingernails can take from 4 to 6 months. Toenails can take twice as long and older age increases all regrowth periods.⁵

Our patient was treated with analgesics until her mucosal surfaces fully healed, and topical emollients and keratolytics were used to soften eschars from previous blisters and prevent further scar formation. Her affected fingernails shed and regrew after 6 months without additional interventions.

Conclusion

Although Stevens-Johnson syndrome is a rare cause of onychomadesis, and the pathophysiology of this sequela is poorly understood, this case illustrates a common nail abnormality with multiple potential etiologies that are discerned by an accurate history and thorough exam. In the absence of decorative nail polish, nails can be easily examined to provide helpful clues for past injuries or underlying diseases. An understanding of nail growth mechanics and associated terminology reveals the diagnostic and therapeutic implications of proximal vs distal nail detachment, the hue of nail discoloration, as well as single vs multiple affected nails.

Onychomadesis in single nails should prompt questions about nail trauma or risk factors for fungal infections. Depending on the etiology, manual activities need to be adjusted, or antifungals need to be initiated while investigating for an immunocompromised state. Onychomadesis in multiple nails in children should raise suspicion for HFMD or even birth trauma and congenital disorders. Multiple affected nails in adults should prompt guided questions for autoimmune diseases and inciting medications. For onycholysis, trauma, psoriasis, or certain infections should be the target. Green nails are easily recognized and treated with a defined regiment, whereas dark nails should be examined closely to differentiate Candida onychia from melanonychia. Whether from a rare cause in an adult to a common illness in a child, primary care providers have sufficient expertise to diagnose and treat various nail disorders and reassure worried patients and parents with an understanding of nail regrowth.

A 45-year-old African American woman presented with painless fingernail detachment and cracks on her fingernails that had developed over the previous month. Her medical history was notable for an episode of Stevens-Johnson syndrome 2 months prior that required treatment with prednisone, IV immunoglobulin, etanercept, acetaminophen, and diphenhydramine.

A physical examination revealed multiple fingernails on both hands that exhibited 4 mm of proximal painless nail detachment with cream-colored discoloration, friability, and horizontal splitting (Figure). New, healthy nail was visible beneath the affected areas. Toenails were not affected.

• What is your diagnosis?
• How would you treat this patient?

Diagnosis

Based on the timing and characteristics of her nail detachment, the patient was diagnosed with onychomadesis, which is defined as painless detachment of the proximal nail plate from the nail matrix and nail bed after at least 40 days from an initial insult. Air beneath the detached nail plate causes a characteristic creamy-white discoloration. The severity of onychomadesis ranges from transverse furrows that affect a single nail without shedding, known as Beau lines, to multiple nails that are completely shed.^1,2 Nail plate shedding is typical because the nail matrix, the site of stem cells and the most proximal portion of the nail apparatus, is damaged and transiently arrested.

Various etiologies can halt nail plate production abruptly within the matrix. These typically manifest ≥ 40 days after the initial insult (the length of time for a fingernail to emerge from the proximal nail fold).² The annual incidence of these etiologies ranges from approximately 1 per 1 million people for Stevens-Johnson syndrome, a rare cause of onychomadesis, to 1 per 10 people for onychomycosis, one of the more common causes of onychomadesis.³ The Table compares the characteristics of the diagnoses that are most commonly associated with nail detachment and discoloration.

When a single nail is affected, the etiology of onychomadesis usually is primary and local, including mechanical nail trauma and fungal nail infections (onychomycosis).^1,2 Candida onychia is onychomycosis caused by Candida species typically Candida albicans, which result in localized nail darkening, chronic inflammation of the paronychial skin, and cuticle loss. The infection favors immunocompromised people; coinfections are common, and onychomadesis or onycholysis can occur. Unlike onychomadesis, onycholysis is defined by painless detachment of the distal nail plate from the nail bed, but nail shedding typically does not occur because the nail matrix is spared. The preferred treatment for Candida onychia is oral itraconazole, and guided screenings for immunodeficiencies and endocrinopathies, especially diabetes mellitus, should be completed.^3,4

Tinea unguium is another form of onychomycosis, but it is caused by dermatophytes, typically Trichophyton rubrum or Trichophyton mentagrophytes, which produce white and yellow nail discoloration followed by distal to proximal nail thickening and softening. Infection usually begins in toenails and demonstrates variable involvement in each nail as well as asymmetric distribution among digits.³ This condition also may eventuate in onychomadesis or onycholysis. Debridement followed by oral terbinafine is the treatment of choice.⁴

Two other causes of localized nail discoloration with or without nail detachment include melanonychia and nail bed infection by Pseudomonas aeruginosa (P aeruginosa). Melanonychia can be linear or diffuse brown discoloration of 1 or more nails caused by melanin deposition. Either pattern is a common finding in dark-skinned people, especially by age 50 years, but melanocyte hyperplasia should be excluded in all individuals along with drug adverse effects, exogenous pigments, infections, and systemic diseases.^3,5 P aeruginosa produces pyocyanin, the green pigment responsible for the discoloration seen in this opportunistic infection often localized to a single nail. Prior maceration of the nail apparatus by repeated water submersion is common among affected individuals. Avoidance of submerging fingernails in liquids followed by nail debridement and oral antipseudomonal antibiotics is the preferred treatment course.³

The etiology is usually secondary and systemic when multiple nails demonstrate onychomadesis, but the exact pathophysiology is poorly understood. One of the most studied infectious etiologies of onychomadesis is hand-foot-and-mouth disease (HFMD), which typically affects children aged < 10 years. Parents often will recall their child being ill 1 to 2 months prior to the nail findings. Scarlet fever and varicella also can result in onychomadesis. Although not common systemic causes, Stevens-Johnson syndrome and toxic epidermal necrolysis can trigger onychomadesis of multiple nails that usually resolves in several months, but other nail deformities often persist.^2,6 Onycholysis also can accompany this finding.⁷ Autoimmune etiologies of onychomadesis include alopecia areata and pemphigus vulgaris. Inciting medications that are toxic to the nail matrix include chemotherapy agents, valproic acid, carbamazepine, lithium, and azithromycin. Rare congenital disorders and birth trauma also can present with onychomadesis of multiple nails during infancy.²

Systemic etiologies typically affect fingernails more than toenails because of the faster growth rate of fingernails. Once the source of onychomadesis is controlled or eradicated, complete regrowth of fingernails can take from 4 to 6 months. Toenails can take twice as long and older age increases all regrowth periods.⁵

Our patient was treated with analgesics until her mucosal surfaces fully healed, and topical emollients and keratolytics were used to soften eschars from previous blisters and prevent further scar formation. Her affected fingernails shed and regrew after 6 months without additional interventions.

Conclusion

Although Stevens-Johnson syndrome is a rare cause of onychomadesis, and the pathophysiology of this sequela is poorly understood, this case illustrates a common nail abnormality with multiple potential etiologies that are discerned by an accurate history and thorough exam. In the absence of decorative nail polish, nails can be easily examined to provide helpful clues for past injuries or underlying diseases. An understanding of nail growth mechanics and associated terminology reveals the diagnostic and therapeutic implications of proximal vs distal nail detachment, the hue of nail discoloration, as well as single vs multiple affected nails.

Onychomadesis in single nails should prompt questions about nail trauma or risk factors for fungal infections. Depending on the etiology, manual activities need to be adjusted, or antifungals need to be initiated while investigating for an immunocompromised state. Onychomadesis in multiple nails in children should raise suspicion for HFMD or even birth trauma and congenital disorders. Multiple affected nails in adults should prompt guided questions for autoimmune diseases and inciting medications. For onycholysis, trauma, psoriasis, or certain infections should be the target. Green nails are easily recognized and treated with a defined regiment, whereas dark nails should be examined closely to differentiate Candida onychia from melanonychia. Whether from a rare cause in an adult to a common illness in a child, primary care providers have sufficient expertise to diagnose and treat various nail disorders and reassure worried patients and parents with an understanding of nail regrowth.

A 25-year-old man presented with multiple sternal cysts that he first noticed when he was aged 18 years and had persisted despite treatment with topical anti-acne agents, including tretinoin. No other medications were used. The patient was unable to express purulent material from the lesions and reported no infection or additional trauma to the affected area. He had no other significant past medical history and no family history of similar skin lesions.

A physical examination revealed an otherwise healthy-appearing male with multiple uniform painless cystic papules scattered across his central chest that were smooth and flesh-colored to slightly yellow-colored, measuring 2 mm to 6 mm in diameter (Figure).  A ring of erythema surrounded the lesions that had been recently manipulated by the patient. There were no overlying central puncta, and the remainder of his body was spared.

Related: Mohs Micrographic Surgery in the VHA

• What is your diagnosis?
• How would you treat this patient?

Diagnosis

The patient was diagnosed with steatocystoma multiplex based on his poor response to topical anti-acne agents, the location of his lesions, and histopathology of a biopsy specimen. Steatocystoma multiplex, sometimes termed sebocystomatosis, typically presents between puberty and the third decade of life. Lesions are usually < 2 cm in diameter and occur as multiple smooth skin-colored or yellow-colored painless papules on areas with high concentrations of hormonally sensitive sebaceous glands, especially the chest. Lesions also can be found in the axillae and on the neck.^1-3 Solitary lesions can occur and are termed steatocystoma simplex.

The timing and location of presentation can easily be mistaken for acne vulgaris, but steatocystoma lesions are true sebaceous cysts, which are rare, and spontaneous resolution with increasing age does not typically occur. The diagnosis of steatocystoma often goes unreported because the disease is usually asymptomatic and mimics more common benign skin conditions, so an accurate prevalence and incidence are both unknown.

First on the differential diagnosis is acne vulgaris, which also presents at puberty and affects nearly 85% of adolescents. However, acne is less common in people of Asian or African descent and may progress along a continuum of increasingly severe and larger lesions, including the primary comedones and papules followed by pustules, nodules, and pseudocysts. Painful lesions develop from inflammation of pilosebaceous units concentrated on the face, neck, trunk, upper arms, or buttocks and are typically worse in males. Resolution often occurs spontaneously by the third decade of life, but scarring can persist.⁴

Related: Using Dermoscopy to Identify Melanoma and Improve Diagnostic Discrimination

Eruptive vellus hair cysts present as dozens of skin-colored small (1-4 mm) painless dome-shaped papules, sometimes with erythema and crusting. Typically these appear on the head, trunk, or flexor surfaces of infants (familial cases) or adolescents (sporadic cases) without bias for gender or ethnicity. Although benign and potential mimickers of steatocystoma and acne, these lesions can also be associated with more serious syndromes, like ectodermal dysplasias and pachyonychia congenita.^2,3

Epidermoid cysts are common benign solitary skin-colored subcutaneous dome-shaped nodules that contain a central punctum through which cheeselike keratinaceous material can be expressed.⁴ These benign lesions arising from the dermis can enlarge to several centimeters, and adults of both genders and most ethnicities tend to develop the lesions on the trunk or face, with small cysts on the face termed milia. Ruptured cysts can incite intense inflammation, and multiple epidermoid cysts should raise concern for Gardner syndrome.^2,3

About This Condition

Steatocystoma lesions are benign and thought to arise from a mutation in keratin 17. The mutation can be inherited in an autosomal dominant pattern, but sporadic nonheritable cases are more common.⁵ There are no distinct associations with gender or ethnicity. The dermal cysts arise from the sebaceous ducts of the pilosebaceous unit, and histopathology typically shows numerous mature sebaceous cells encased by a thin wall of stratified squamous epithelium.² Immunohistochemical staining for the defective keratin can help diagnose biopsy specimens, and histopathology confirmed the diagnosis in this case.

Related: Recurring Bilateral Rash Concomitant With Upper Respiratory Tract Infection in a Healthy Adult Male

Treatment

Steatocystoma is usually asymptomatic, so patients mainly present to physicians for cosmetic reasons. Puncturing the cyst wall within the dermis produces translucent sebum-containing fluid, and ruptured cysts can incite inflammation, pain, and scarring.² However, prognosis is good, and treatment consists of excision, aspiration and curettage of the cyst wall, oral isotretinoin, or laser therapy. Our patient elected to forego treatment and will consider definitive removal in the future, since the lesions will persist and potentially enlarge. Accurate diagnosis of this rare cause of chest papules improves the timeliness and efficacy of appropriate treatment, favoring good cosmesis.

A 25-year-old man presented with multiple sternal cysts that he first noticed when he was aged 18 years and had persisted despite treatment with topical anti-acne agents, including tretinoin. No other medications were used. The patient was unable to express purulent material from the lesions and reported no infection or additional trauma to the affected area. He had no other significant past medical history and no family history of similar skin lesions.

A physical examination revealed an otherwise healthy-appearing male with multiple uniform painless cystic papules scattered across his central chest that were smooth and flesh-colored to slightly yellow-colored, measuring 2 mm to 6 mm in diameter (Figure).  A ring of erythema surrounded the lesions that had been recently manipulated by the patient. There were no overlying central puncta, and the remainder of his body was spared.

Related: Mohs Micrographic Surgery in the VHA

• What is your diagnosis?
• How would you treat this patient?

Diagnosis

The patient was diagnosed with steatocystoma multiplex based on his poor response to topical anti-acne agents, the location of his lesions, and histopathology of a biopsy specimen. Steatocystoma multiplex, sometimes termed sebocystomatosis, typically presents between puberty and the third decade of life. Lesions are usually < 2 cm in diameter and occur as multiple smooth skin-colored or yellow-colored painless papules on areas with high concentrations of hormonally sensitive sebaceous glands, especially the chest. Lesions also can be found in the axillae and on the neck.^1-3 Solitary lesions can occur and are termed steatocystoma simplex.

The timing and location of presentation can easily be mistaken for acne vulgaris, but steatocystoma lesions are true sebaceous cysts, which are rare, and spontaneous resolution with increasing age does not typically occur. The diagnosis of steatocystoma often goes unreported because the disease is usually asymptomatic and mimics more common benign skin conditions, so an accurate prevalence and incidence are both unknown.

First on the differential diagnosis is acne vulgaris, which also presents at puberty and affects nearly 85% of adolescents. However, acne is less common in people of Asian or African descent and may progress along a continuum of increasingly severe and larger lesions, including the primary comedones and papules followed by pustules, nodules, and pseudocysts. Painful lesions develop from inflammation of pilosebaceous units concentrated on the face, neck, trunk, upper arms, or buttocks and are typically worse in males. Resolution often occurs spontaneously by the third decade of life, but scarring can persist.⁴

Related: Using Dermoscopy to Identify Melanoma and Improve Diagnostic Discrimination

Eruptive vellus hair cysts present as dozens of skin-colored small (1-4 mm) painless dome-shaped papules, sometimes with erythema and crusting. Typically these appear on the head, trunk, or flexor surfaces of infants (familial cases) or adolescents (sporadic cases) without bias for gender or ethnicity. Although benign and potential mimickers of steatocystoma and acne, these lesions can also be associated with more serious syndromes, like ectodermal dysplasias and pachyonychia congenita.^2,3

Epidermoid cysts are common benign solitary skin-colored subcutaneous dome-shaped nodules that contain a central punctum through which cheeselike keratinaceous material can be expressed.⁴ These benign lesions arising from the dermis can enlarge to several centimeters, and adults of both genders and most ethnicities tend to develop the lesions on the trunk or face, with small cysts on the face termed milia. Ruptured cysts can incite intense inflammation, and multiple epidermoid cysts should raise concern for Gardner syndrome.^2,3

About This Condition

Steatocystoma lesions are benign and thought to arise from a mutation in keratin 17. The mutation can be inherited in an autosomal dominant pattern, but sporadic nonheritable cases are more common.⁵ There are no distinct associations with gender or ethnicity. The dermal cysts arise from the sebaceous ducts of the pilosebaceous unit, and histopathology typically shows numerous mature sebaceous cells encased by a thin wall of stratified squamous epithelium.² Immunohistochemical staining for the defective keratin can help diagnose biopsy specimens, and histopathology confirmed the diagnosis in this case.

Related: Recurring Bilateral Rash Concomitant With Upper Respiratory Tract Infection in a Healthy Adult Male

Treatment

Steatocystoma is usually asymptomatic, so patients mainly present to physicians for cosmetic reasons. Puncturing the cyst wall within the dermis produces translucent sebum-containing fluid, and ruptured cysts can incite inflammation, pain, and scarring.² However, prognosis is good, and treatment consists of excision, aspiration and curettage of the cyst wall, oral isotretinoin, or laser therapy. Our patient elected to forego treatment and will consider definitive removal in the future, since the lesions will persist and potentially enlarge. Accurate diagnosis of this rare cause of chest papules improves the timeliness and efficacy of appropriate treatment, favoring good cosmesis.

A 25-year-old man presented with multiple sternal cysts that he first noticed when he was aged 18 years and had persisted despite treatment with topical anti-acne agents, including tretinoin. No other medications were used. The patient was unable to express purulent material from the lesions and reported no infection or additional trauma to the affected area. He had no other significant past medical history and no family history of similar skin lesions.

A physical examination revealed an otherwise healthy-appearing male with multiple uniform painless cystic papules scattered across his central chest that were smooth and flesh-colored to slightly yellow-colored, measuring 2 mm to 6 mm in diameter (Figure).  A ring of erythema surrounded the lesions that had been recently manipulated by the patient. There were no overlying central puncta, and the remainder of his body was spared.

Related: Mohs Micrographic Surgery in the VHA

• What is your diagnosis?
• How would you treat this patient?

Diagnosis

The patient was diagnosed with steatocystoma multiplex based on his poor response to topical anti-acne agents, the location of his lesions, and histopathology of a biopsy specimen. Steatocystoma multiplex, sometimes termed sebocystomatosis, typically presents between puberty and the third decade of life. Lesions are usually < 2 cm in diameter and occur as multiple smooth skin-colored or yellow-colored painless papules on areas with high concentrations of hormonally sensitive sebaceous glands, especially the chest. Lesions also can be found in the axillae and on the neck.^1-3 Solitary lesions can occur and are termed steatocystoma simplex.

The timing and location of presentation can easily be mistaken for acne vulgaris, but steatocystoma lesions are true sebaceous cysts, which are rare, and spontaneous resolution with increasing age does not typically occur. The diagnosis of steatocystoma often goes unreported because the disease is usually asymptomatic and mimics more common benign skin conditions, so an accurate prevalence and incidence are both unknown.

First on the differential diagnosis is acne vulgaris, which also presents at puberty and affects nearly 85% of adolescents. However, acne is less common in people of Asian or African descent and may progress along a continuum of increasingly severe and larger lesions, including the primary comedones and papules followed by pustules, nodules, and pseudocysts. Painful lesions develop from inflammation of pilosebaceous units concentrated on the face, neck, trunk, upper arms, or buttocks and are typically worse in males. Resolution often occurs spontaneously by the third decade of life, but scarring can persist.⁴

Related: Using Dermoscopy to Identify Melanoma and Improve Diagnostic Discrimination

Eruptive vellus hair cysts present as dozens of skin-colored small (1-4 mm) painless dome-shaped papules, sometimes with erythema and crusting. Typically these appear on the head, trunk, or flexor surfaces of infants (familial cases) or adolescents (sporadic cases) without bias for gender or ethnicity. Although benign and potential mimickers of steatocystoma and acne, these lesions can also be associated with more serious syndromes, like ectodermal dysplasias and pachyonychia congenita.^2,3

Epidermoid cysts are common benign solitary skin-colored subcutaneous dome-shaped nodules that contain a central punctum through which cheeselike keratinaceous material can be expressed.⁴ These benign lesions arising from the dermis can enlarge to several centimeters, and adults of both genders and most ethnicities tend to develop the lesions on the trunk or face, with small cysts on the face termed milia. Ruptured cysts can incite intense inflammation, and multiple epidermoid cysts should raise concern for Gardner syndrome.^2,3

About This Condition

Steatocystoma lesions are benign and thought to arise from a mutation in keratin 17. The mutation can be inherited in an autosomal dominant pattern, but sporadic nonheritable cases are more common.⁵ There are no distinct associations with gender or ethnicity. The dermal cysts arise from the sebaceous ducts of the pilosebaceous unit, and histopathology typically shows numerous mature sebaceous cells encased by a thin wall of stratified squamous epithelium.² Immunohistochemical staining for the defective keratin can help diagnose biopsy specimens, and histopathology confirmed the diagnosis in this case.

Related: Recurring Bilateral Rash Concomitant With Upper Respiratory Tract Infection in a Healthy Adult Male

Treatment

Steatocystoma is usually asymptomatic, so patients mainly present to physicians for cosmetic reasons. Puncturing the cyst wall within the dermis produces translucent sebum-containing fluid, and ruptured cysts can incite inflammation, pain, and scarring.² However, prognosis is good, and treatment consists of excision, aspiration and curettage of the cyst wall, oral isotretinoin, or laser therapy. Our patient elected to forego treatment and will consider definitive removal in the future, since the lesions will persist and potentially enlarge. Accurate diagnosis of this rare cause of chest papules improves the timeliness and efficacy of appropriate treatment, favoring good cosmesis.